Update README.md

docs/learning-tf-zh/README.md

@@ -6,6 +6,8 @@
 > 
 > 协议：[CC BY-NC-SA 4.0](http://creativecommons.org/licenses/by-nc-sa/4.0/)
 >
+> 阶段：精细校对（4）
+> 
 > 自豪地采用[谷歌翻译](https://translate.google.cn/)
 
 + [在线阅读](https://www.gitbook.com/book/wizardforcel/learning-tf/details)